Vintage Men’s Navajo SC Sharon Cisco Sterling Silver 3 Turquoise Ring Sz 15? This is a neat vintage men’s Navajo SC Sharon Cisco Sterling Silver 3 Turquoise ring. It is in good to very good condition. Ring is a size 15? . My ring mandrel only goes up to a 13 size, so I did an approximate size. Marked SC and Sterling on the inside. Weighs 7.1 grams. View my photos for details. Please contact me if you have any questions.